This invention relates to a method of using nicotine in the treatment of conditions susceptible to such treatment.
Nicotine is the major alkaloid of tobacco and is the most potent alkaloid in tobacco smoke.
Nicotine has been shown to act as a primary reinforcer in animals and many of its pharmacological effects are potentially rewarding. It induces tolerances and smokers suffer from physical, as well as, subjective effects when it is withdrawn.
Nicotine also induces changes in the number of nicotinic cholinergic receptors and this is one possible mechanism underlying tolerance. Besides its main direct action at nicotinic cholinergic receptor sites, through linkage of these sites with other neurotransmitter systems, nicotine has indirect effects on the release of most of the known neurotransmitters. Through its action on the locus coeruleus it has a widespread effect on noradrenergic activity throughout the brain. It also activates ascending dopaminergic pathways thought to be involved with the brainstem and hypothalamic reward systems. Its effect on dopaminergic activity may link in with the lower incidence of Parkinson's disease among cigarette smokers. Nicotine also stimulates cholinergic neurones in the nucleus basalis of Meynert which in turn project to all regions of the cortex. This and similar actions on nerve cells in the septum, which project to the hippocampus, may be involved in the effect of nicotine on memory processes.